The sony lens has an effective F stop of 2.4 at the short end and an effective F stop of 3.4 at the long end. Numerically, this calculates to an F stop change of 1.01 in terms of the amount of glass size at either end which means slightly over a 50% reduction at the long end over the short. Its a log function, an example (f 2.8 to f 4.0 is 1 full F stop or a reduction of 50%). In terms of light gatrher power the lens is 50% slower at the long end. Since we know the lumens out on one sample close throw, it would seem that one could calculate the amount out at long throw but it isn't that simple because only a small portion of the lens area is used at either end. Perhaps Coderguy can use the effective f stops I posted in his calculator. I haven't looked at it yet. Maybe it already does.

BTW, I am somewhat jealous of this projector, but I just have to own an RS-45 before I can own a Sony again or convince myself to dump this much money in one unit (don't listen to me though guys, we all have different budgets). This projector sounds really strong across the board and very well balanced, and if the JVC doesn't satisfy I may very well be spending more and looking at this unit next. It sounds like it will beat the JVC's overall I think since it has the better motion.

Also, Rick's numbers are pretty close to my calculators, although his fL are a bit lower at farthest throw than what my calculator shows. I think the calculator is close enough since there is some variance in measurement equipment and even on new lamps.

Added:
I actually ended up going with 35% as the number, so 20% as a loss from mid-zoom position, and 15% as an increase from mid zoom. People can change these numbers manually in my calculator if they prefer, as the boxes are editable.

Yes. Its rather simple. At closest throw the image coming out of the lens is wider and taller than it is ant any other throw. The piupe size if you wil of the lens is its widest at that point. The light falls off as one goes towards longer throw. The fall off is a log function and the lpg numbers at either end are specified or can be calculated. What this means is that the flaa off slope is steep and moving just a bit from closest throw contributes a substantial portion of the fall off. By mid throw the line is flattening. I yield to Coderguy but I think the calculator needs to employ a log function measured from say the short end rather than trying to make two curves, each at one end to the middle.

I kind of laugh at people who think placing a projector at mid throw is the sweet spot. It gives one pretty close to low lumens and high on of CR. One really has to choose what is more important to them. One needs a certain amount of on off in real life to run the gamma of their choice. Once you have enough placing to get higher lumens would normally be more important than raising the on off by x 1000s.

Shortest throw (closest to the screen) gives you the maximum brightness for a given screen size.

Although when it comes down to it, you also can look at screens with various gains as an alternative to mounting it closer (or both to really pump up the lumens). For a budget screen, the Da-Lite High Power 2.4 gain screen should do ok with this projector as long as you are not having big movie events with multiple people in the room (in which case the seating affects brightness due to angle). There are many other screen choices you can look at such as some with moderate gains 1.3 to 1.5, and some do produce a slightly better image than the HP screen (but usually at a higher cost), and the HP is on the higher end of the gain, but I do like the HP because by adjusting the mounting position you can change the gain you get.

Like Mark said, with today's projectors and quality, there is usually a very very minor difference in PQ from shortest to farthest throw, with brightness being the main factor. Especially in this price range with the superb lens's of a projector like vw95es, if we were talking about a DLP or something, I tend to try to squeeze every last bit of native contrast out of it since that is the DLP's weakness, but for a projector like this, it doesn't really matter.

Unless the image is just too bright for your setup, I'd say get the projector mounted pretty much as close as possible to preserve lumens and lamp life, and for those extra 3D lumens it is more important to mount it closer. If it is too bright such as you are using a very small screen, then try to mount it farther back. Mounting position should be based on brightness really over the other factors. I have an HP screen so I can mount things farther back than some can, but it doesn't help much most of the time, I just like to pretend it does (OCD delusions)...

Does the VW95 have something like JVC's lens aperture feature where you can adjust the brightness without having to move the projector (if the picture is too bright for example)?

Quote:

Originally Posted by misterkit

So what is the ideal zoom?

The ideal zoom is the one that works best for your room. Everybody's room is different and it really is a matter of opinion. Some good advice is put the projector as close as you can (but not too close) for good brightness.

From what I remember, with the Sony's if you close the IRIS, you lose the dynamic IRIS ability. However, I do not think that is a big deal at first until the lamp wears in. So I'd say you can control the brightness fairly well on the Sony's, I'm not sure if the Sony vw95 has a DUAL implementation to allow a separate adjustment beyond the single IRIS, but the hw30 only had a DI that can be used like a manual or a dynamic IRIS, but not both if I remember correctly.

My numbers in the calculator for IRIS closed do not mean anything yet, as I do not have any reliable numbers for this.

Perhaps RickAV Maniac will measure IRIS closed for me?

The calculator isn't perfect by any means, but it definitely gives you a good idea generally with an error margin of less than 15%. Other calculators I have seen are +- 50% or more usually, and 15% one way or another is hard to see by eye anyhow.

Right - thank you SO MUCH for doing this. I know it is a real PITA to move the pj around to do this type of testing, especially once you have it set up where you want it.

Its pretty disappointing to hear that we are looking at basically a 30% drop in lumens from shortest to longest, as I will be mounting basically at the longest.

So if we take Kraine's 495 lumens at shortest throw... oh wait technically he wasn't at shortest throw but pretty close - ok let's give the pj the benefit the doubt and add 5% to that - so let's call it 520 lumens at shortest throw...

OK so we take 520 and drop it 30% we are at 364 lumens for longest throw (low lamp). On my 106" diag 1.3 gain Firehawk that will yield about 14.3ftL. Ironically that is right about where I am now with my RS20 (just measured yesterday) at 117 hours on the bulb. The brightness is acceptable with the RS20, so I know it will be acceptable with the Sony. That said, it would have been nice to get a 10-20% boost in this area.

And supposedly the bulb is reasonably priced. I usually don't put more than 200-300 hours a year on a bulb, so if I need to replace a bulb at 300 hours once a year its worth it to have the pj.

So Rick - one thing I was thinking is that if the brightness does bother me I could just run in high lamp mode. Considering how quiet it is in that mode, that is an option with this pj unlike with most others. So then the real question becomes - how much is the black level affected by running in high lamp mode. Since the whites become that much brighter, sometimes it can trick your eye into thinking the blacks are just as dark because relative to the extra bright whites the blacks seem nice and black. Thoughts?

The vw95 has several improvements over the hw30, and my feeling is that the improvements are worth it for many, but not everyone of course, depends on your budget. The vw95 seems to have better convergence on average, and convergence still matters even if you have convergence correction ability. The vw95 also has a few more features (see earlier lists in this thread). The native CR measurements that were taken earlier in the thread are also not 100% perfect (none are) and since at these levels of native CR it is difficult to get the reading perfect, you need a sensitive light meter instead of a colorimeter or a calibration device. I expect we will see a slightly larger variation in native CR once Cine4's measurements are finished.

My bets are that in most cases there will not be a huge difference between perceivable brightness between the JVC or the Sony after a couple hundred hours, just a guess though and this is not an exact science.

Zombie,
I think Joerod still have both in is room. If so, he will be able to answer that one for sure...

Sorry to bother you again, and there is no rush, but when you get a chance can you take an IRIS closed reading in low and high lamp mode at closest or far throw (whichever is easier so you don't have to move the PJ).

I know Joe. He can still work on projectors as look as she keeps the skirt on. Its after that he loses his concentration. I called him late one night. I ask him if he could answer about a specific projector he was playing with. I don't remember which specific one it was.

He answered projector? What projector?. Then he concluded with that famous James Bond line. Gotta go Mark. Something big has come up.

Kutlow. You ask the question. The HW30ES is good. The VW95ES is noticeably better. It has better contrast and it is noticeably sharper not that the HW30ES isn't sharp when you move back a few feet from the screen.

Is it worth the difference. Noone can answer that question for you. It depends on what one can afford to spend and how much the better PQ is to you. Its a value judgement. Pure and simple. To me the cost differential is affordable and being a sharpness freak the sharpness improvement is worth it to me. But that is me. Not you. And only you can answer that question.

I dont know how you have time to work on projectors when you have that beautiful fiance prancing around in tight skirts!

Sorry.

I ended up passing out candy and then using the 95 to watch MonsterHouse 3D!
I absolutely promise on Tuesday I will post. At this point I am crossing Ts and just dotting the last few Is.. which is why I am awake.

I just received my VW95 and I try to calibrate with my i1Pro and my Lumagen XS3D. I came from JVC X3 and there was no Dynamic Iris. So I initially adjust it with DI ON, but the results are catastrophic!

I find out that DI should be always OFF when you calibrate the VW95. What I'm also wonder is the Custom Color Temp Settings. I really have to lower blue to almost -30 to get close to 6500k. If red drops than I can't reach 6500k with so much blue...

Any suggestion how to calibrate the VW95 together with an Lumagen? I always get 100IRE to 6500k with all colors at 100%, than I use the 11 point Gamma of the Lumagen to adjust 90-0 IRE. Should I consider something different with the Sony?

Sorry to bother you again, and there is no rush, but when you get a chance can you take an IRIS closed reading in low and high lamp mode at closest or far throw (whichever is easier so you don't have to move the PJ).